1. Field of the Invention
The present invention relates to structures used for documents in data and word processing systems and more particularly to apparatus, methods, systems, and structures used to translate a document having one structure into an equivalent document having another structure.
2. Description of the Prior Art: FIG. 1
Documents may be written and processed using many different kinds of data processing or word processing systems. Documents processed using a given system have a document structure specific to that system. Thus, if a document is to be processed first on one system and then on another, it must be translated from a document having the structure required for the first system into a document having the structure required for the second system. In the prior art, translation from one structure to another was accomplished by writing a translation program specific to the two structures. The consequences of this approach are shown in prior-art FIG. 1. In that Figure, there are represented four versions of a document, version 101 having structure A, version 103 having stucture B, version 105 having structure C, and version 107 having structure D. Six programs, represented by the boxes labelled 109, 111, 113, 115, 117, and 119, are necessary to permit translation of a version having any one of the structures into a version having any of the other structures. As further structures are added, the number of translation programs required increases disproportionately. If all translations may be made in either direction, the number of translation programs N required for a number of structures n is expressed by N=(n-1)+(n-2)+..+(n-(n-1)). Moreover, in order to write each of the translation programs, a detailed knowledge of both document structures is required. That requirement is disadvantageous in two respects. First, if translation programs are to be provided for any considerable number of structures, the programmer must spend a great deal of time studying the structures. Second, where one of the document structures is confidential and proprietary to one manufacturer and the other is confidential and proprietary to another, the knowledge required to write a translation program for the structures may be unobtainable.